nRF52832 Shutting Down After 30 Seconds on Custom Hardware

[Charindu]

Hi everyone,

I'm working with the nRF52832 on custom hardware, and I'm experiencing an issue where the microcontroller shuts down after around 30 seconds, regardless of the firmware flashed. Here's some more context on the situation:

Hardware Overview:

• Custom PCB featuring the nRF52832 (MDBT42V module).
• Power circuit includes the TPS70933 LDO and LTC2955-1 push-button controller with a PWR_SHDN signal to control power-off.
• External EEPROM (AT25) connected over SPI, and several LEDs controlled via GPIO.
• The nRF52832 is programmed using J-Link.

Problem Description:

• When I flash simple code such as a basic Blinky application (toggling an LED), the microcontroller shuts down after around 30 seconds.
• I tried erasing the chip using J-Link and reflashing it, but the issue persists on this particular board.
• Interestingly, the same Blinky code works perfectly fine on another nRF52832 , suggesting the problem is specific to this custom hardware.
• PWR_SHDN signal is controlled by the LTC2955-1 IC, and I suspect this could be causing the shutdown, but I’m not entirely sure how to bypass it or debug it further.
  
  
  Has anyone else faced a similar issue or can offer insights on what might be causing the shutdown? Any advice on how to properly debug

[Priyanka]

Hi,

The issue could be maybe because of a PWR_SHDN signal coming form the LTC2955-1. Could you check whether a PWR_SHDN signal is being triggered after 30s? You could use an oscilloscope for this.

Maybe try to temporarily bypass the power shutdown just to verify if this is the issue. Maybe by disconnecting the PWR_SHDN signal or maybe manually keeping the power on through a jumper (if your design allows it).

-Priyanka